Submersible combined centrifugal and jet pump



March 11, 1958 w. ERNST 2,326,148

SUBMERSIBLE COMBINED CENTRIFUGAL AND JET PUMP Filed Dec. 11, 1955 2 INVENTOR.

WALTER ERNST BY 67 z #7 g ATTORNEYS SUBMERSIBLE COMBINED CENTRIFUGAL AND JET PUMP Walter Ernst, Dayton, Ohio, assignor to The Commonwealth Engineering Company of Ohio, Dayton, ()hio, a corporation of Ohio Application December 11, 1953, Serial No. 397,698

3 Claims. (Cl. 103-5) This invention relates to pumping arrangements, and more particularly to submersible pumping arrangements adapted for being inserted into a well casing. More particularly still this invention relates to a submersible jet pumping arrangement having in combination a jet pump and a centrifugal pump, in which both the jet pump and the centrifugal pump are inserted into a well casing.

in the pumping of wells it is quite customary to combine a jet pump with a centrifugal pump, the jet pump being employed for driving water to the inlet of the centrifugal pump and with the discharge side of the centrifugal pump being connected to service. The jet pump portion of such a combination can be directly associated with the centrifugal pump, or it can be located within a well and discharge into a conduit leading to the suction side of the centrifugal pump that is located outside the well. This latter arrangement is useful for deep well installations, and the former arrangement is useful for shallow wells.

in other instances pumps have been constructed which are adapted for operating submerged in the well, particu larly centrifugal pumps, and in which case the pumps are either driven by a directly connected electric motor or by a long shaft leading down the well casing to the pump. The directly connected electric motor arrangement is somewhat at fault in that it is difficult to seal the electric motor against the entrance of well water and to service the electric motor, which is generally required at more or less frequent intervals. It is difficult because it is necessary to pull the motor and pump from the well casing.

The long shaft method of driving a submersible pump is obviously a poor arrangement because of the weight and expense of the long shaft and the impossibility of driving a shaft of this nature at sufficiently high speed to obtain efiicient pumping resultswithout the shaft commencing to whip.

Having the foregoing in mind, it is a primary object of this invention to provide a pumping arrangement con sisting essentially of a combination of a centrifugal pump and a jet pump forming a single unit, and with the unit being adapted for being located in a submerged position within a well casing.

Another object of this invention is the provision of a combination of a jet and a centrifugal pump adapted for submerged operation and including a hydraulic motor means for driving the centrifugal pump.

A further object of this invention is the provision of a combination of a submerged jet and centrifugal pump with a drive motor directly connected therewith, but which drive motor is adequately sealed against the entrance of well water therein.

A still further object of this invention is the provision of a combination jet and centrifugal pump adapted for being located in a submerged position in a well casing and having a drive motor directly associated therewith for driving the pump at high speed.

Still another object of this invention is the provision of a pumping arrangement adapted for operating at a nited States Patent ice submerged location within a well casing, and which pumping arrangement can readily be adjusted vertically within the well casing for obtaining the most eflicient operating conditions.

These and other objects and advantages of this invenwill become more apparent upon reference to the following specification taken in connection with the accompanying drawings, in which:

Figure 1 is a vertical sectional view, more or less diagrammatic, showing a pumping installation according to my invention;

Figure 2 is a vertical section through the pump and drive motor of Figure 1;

Figure 3 is a sectional view indicated by line 3--3 on Figure 2 showing a valve plate forming a part of the hydraulic motor which drives the pump; and

Figure 4 is a sectional view indicated by line 4-4 on Figure 2 showing the inlet to the jet pump, a portion of the chamber surrounding the venturi of the jet pump, and the chamber through which water is supplied to the jet of the jet pump.

Referring to the drawings somewhat more in detail, the pumping installation illustrated in Figure 1 consists of a well casing ill extending downwardly into the earth into a water bearing strata and having its lower end open as at 12. Located in a lower portion of casing 10, with at least the lower end thereof submerged in the water in the well, is a pumping unit generally designated 14. This pumping unit has a screened inlet opening 16 through which it draws water from the well casing, and also has a discharge pipe 18 leading upwardly through well casing 10 and connected with a service conduit 20.

The unit 14 consists of a hydraulic drive motor to which fluid under pressure is supplied through a conduit 22 and fluid is exhausted therefrom through a conduit 24, these latter conduits leading upwardly through well casing 10 and out through the top plate 26 thereof. The conduits 22 and 24, together with conduit 18, can serve as a means for supporting unit 14 within the well casing.

A tank 28 located adjacent the top of the well casing supplies fluid to the hydraulic pump 30 driven by a motor 32, and which pump 30 has its discharge side connected with pressure conduit 22. Exhaust conduit 24 leads to tank 28 and it will be apparent that energization of motor 32 to drive pump 30 will bring about a supply of fluid under pressure to the aforementioned hydraulic motor for causing the said motor to run, thereby actuating the pump of unit 14.

Referring now to Figures 2, 3 and 4, the construction of the pump and hydraulic motor of unit 14 is illustrated more in detail. In Figure 2 it will be observed that unit 14 consists of an upper casing portion 34 within which is mounted a cylinder block 36 having a plurality of axial bores therein reciprocably receiving plungers 38, the lower rounded ends of which bear on the wobble plate 46 that is connected with shaft 42 that has bearing means supporting it as at 44 and 46 in the cylinder block.

Still another bearing is at 48 rotatably supporting shaft 42 where it passes through a lower wall of easing part 34, and this lower wall also preferably has mounted therein a fluid seal 50 surrounding shaft 42.

Keyed to the upper end of shaft 42 and slidably engaging the upper end of cylinder block 36 is a valve plate 52 having an annular groove 54 that is in continuous communication with pressure conduit 22 by channel 56, and a of casing 34 and is provided with a recess for receiving the upper end of the cylinder block and the valve plate, and

assume at is likewise provided with threaded openings communicating with the aforementioned channels, which openings receive the ends of conduits 22 and 24.

On the side of valve plate 52, where it engages cylinder block 36, there are the arcuate passages 62 and 64 that register with the upper open ends of the bores in the cylinder block. Groove 62 is continuously connected with pressure groove 54, while groove 64 is continuously connected with exhaust groove 58. In a manner well known in the art the valve plate 62 will rotate with shaft 42 so as to connect pressure groove 64 with those of plungers 38 that are moving downwardly while simultaneously connecting exhaust groove 62 with those of plungers 38 that are moving upwardly. Those of the plungers which are changing their direction of movement will be located between the ends of grooves 62 and 64.

Shaft 42 extends downwardly into a lower casing part 66 of unit 14 and within which casing part there are located a plurality of centrifugal pumping stages 6%, 7d, 72 and 74; each such stage consisting of a centrifugal impeller and a housing portion. The periphery of the impeller of the third stage, that is stage 72, is connected with a channel 76 leading to discharge conduit 18. The inlet of the first pumping stage, that is pumping stage 68, opens into a chamber '78 in which is mounted Venturi tube 80. Venturi tube 30 has its inlet opening into chamber 82 that communicates directly with screened opening 16 re ferred to previously. The inlet of Venturi tube 80 is also arranged to receive ajet of fluid from a nozzle 84 that is connected by passage means 86 with the periphery of the impeller of the fourth pumping stage 74.

It will be apparent that when the hydraulic motor is energized to rotate shaft 42, water will be delivered to discharge conduit 18 by the impeller of the third pumping stage, while a portion of the water delivered from this pumping stage will be passed through the impeller of the fourth pumping stage to be delivered at increased pressure to nozzle 84 which will supply a jet to Venturi tube 80, thus creating a high suction in the Venturi tube which will augment the flow of water inwardly through screened opening 16 into chamber 82 and thence through Venturi tube 80 to chamber 78 and the inlet of the impeller of the first stage 63 of the centrifugal pump.

It will be observed that with the entire pumping unit located in a submerged portion within the well, the cooperation of the jet pump and the centrifugal pump will be extremely efficient. The pump will at all times he primed by the very water in the well, and the only thing necessary to commence the pump to working is to energize the hydraulic motor. Inasmuch as the entire pumping unit is submerged in the water within the well there will be little or no problem of air separation so that .expensive and complex air separating chambers and the like associated with the pump are not required.

It will be seen that the particular type of hydraulic motor illustrated is only exemplary of many types of hydraulic units that could be employed for driving the pump. Similarly, the pump itself is subject to modification, as, for example, withdrawing the water for supplying the jet from one of the earlier stages of the pump while connecting the final stage of the pump with the di charge conduit. It will likewise be appreciated that by utilizing a hydraulic motor for driving the pump the interior of the hydraulic pump can be maintained under pressure so that there will be no leakage of water into the pump, thus eliminating any problems of servicing the hydraulic motor, except at quite infrequent intervals.

It .will be understood that this invention is susceptible to modification in order to adapt it to different usages and conditions, and, accordingly, it is desired to comprehend such modifications within this invention as may [fall within the scope of the appended claims.

I claim:

1. A submersible pump arrangement for a well casing having a quantity of water therein comprising a source of pressure fluid outside of said casing, 'a hydraulic motor in said casing, a pumping unit secured below said hydraulic motor and comprising a multi-stage centrifugal pump driven by said hydraulic motor and discharging pumped water from an intermediate stage thereof, a jet pump delivering a stream of pressure fluid to the inlet of said centrifugal pump and means in said pumping unit for supplying pumped water to the nozzle of said jet pump at a pressure higher than that of the water being discharged from said centrifugal pump, said jet pump and centrifugal pump being submerged at all times in the water in the well casing whereby said jet pump will augment the flow of water into the inlet of the centrifugal pump upon energization of the hydraulic motor.

2. In a submersible pump arrangement for a well cashaving a quantity of Water therein, a source of pressure fluid outside of said casing, a hydraulic motor within said casing operable by the fluid pressure from outside of said casing, a multi-stage centrifugal pump having a discharge and connected to said hydraulic motor with the pump impellor being driven by said hydraulic motor, and the next to the final stage delivering water to said centrifugal pump discharge, a jet pump serially connected to said centrifugal pump and delivering a stream of pumped water to the inlet of said centrifugal pump, means providing a passage between the final stage of said centrifugal pump impellor and the nozzle of the jet pump for supplying pumped water to the jet pump at a higher pressure than the water delivered from the centrifuga pump discharge, said hydraulic motor, centrifugal pump and jet pump being submerged at all times in the water within said well casing whereby said jet pump will augment the flow of water into the intake of the centrifugal pump upon energization of the hydraulic motor.

3. In a submersible pump arrangement for a well cas ing having a quantity of water therein, a source of pressure fluid outside of said casing, a pumping unit comprising a jet pump having its inlet communicating to the Water in the well casing and a multi-stage centrifugal pump with a discharge opening and having its inlet communicating with the discharge of said jet pump with means defining a passage from the last stage of said centrifugal pump to the nozzle of said jet pump, the next preceding stage pumping water to both the discharge of the centrifugal pump and to the final stage thereof, whereby water is pumped to said jet pump nozzle at a higher pressure than to the centrifugal pump discharge, a hydraulic motor operable by the fluid pressure outside of said Well casing and attached to said pumping unit and connected to said centrifugal pump to drive the impellor thereof, conduit means connecting said source of fluid outside of said casing and said hydraulic motor and supporting said pumping unit and hydraulic motor within said well casing, said hydraulic motor and pumping unit being submerged at all times whereby said jet pump will augment the flow of water into the inlet of the centrifugal pump upon energization of the hydraulic motor.

References Cited in the file of this patent UNITED STATES PATENTS 1,042,227 Hogel Oct. 22, 1912 2,102,140 Ungar Dec. 14, 1937 2,344,958 Armstrong Mar. 28, 1944 2,403,555 Ruth July 9, 1946 2,424,285 Piccardo et a1. July 22, 1947 2,466,792 Conery Apr. 12, 1949 2,577,559 Armstrong Dec. 4, 1951 2,634,680 Schleyer Apr. 14, 1953 2,651,998 Bergh Sept. 15, 1953 2,657,641 Lung Nov. 3, 1953 2,710,579 Kriegbaum June 14, 1955 FOREIGN PATENTS 554,122 Great Britain a June 22, 1943 

